摘要:

This article reviews the experimental induction of ameloblastomas with emphasis on the acceptability of the induced tumors as being truly equivalent to amelobastomas in humans. Attempts to induce odontogenic tumors in experimental animals have been made sporadically since the early 1960's but the yield of ameloblastomas has been low. Tumors resembling ameloblastomas. but not completely typical histologically and apparently lacking the invasive qualities of ameloblastoma, have been produced in mice using polyoma virus. However, the most typical ameloblastomas have been those induced in opossums, using ethylnitrosourea. Consequently, it is recommended that this model be used in any further attempts to produce ameloblastomas experimentally.

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01360.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Dental hard tissues and mineralization at the enamel surface or in the ameloblastic epithelium were studied in 10 odontomas using undemineralized material. All the specimens showed a high degree of histo‐ and morphodifferentiation. Dentin formed the bulk of the tumors. Much of the enamel was prismatic and apparently normal and in almost every specimen were present enamel tufts and spindles. At greater magnification it could he seen that the prisms had a very irregular orientation. Cementum was mostly acellular. Calcified material formed focally in the intercellular portion of the enamel epithelium: this material showed a concentric layers arrangemen

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01361.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Actinomyces viscosusstrains, freshly isolated from root surface caries lesions and intact root surfaces, were studied for their glycogen synthetic and degradative activities at pH 4.5, 5.0, and 7.0 in a pH‐stat. At all three pH levels, root caries origin ofA. viscosussynthesized up to three times as much glycogen compared to non‐root caries origin. Since root caries origin ofA. viscosusstrains initially synthesized large amounts of glycogen, a longer period of time was required to deplete this polymer, resulting in an extended period of acid production, even at pH 4.5 and pH 5.0. This study suggests that the ability ofA. viscosusof root caries origin to synthesize large quantities of glycogen and subsequently degrade this stored polymer slowly with acid production, at acidic pH levels, may play an important role in the root caries proc

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01362.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Three rare variants of the adenomatoid odontogenic tumor (AOT) are described. A follicular AOT associated with an impacted and displaced 28, an extra‐follicular variant mimicking a radicular cyst around the apex of 23 and a peripheral (epulis‐like) variant exhibiting a periodontal bone defect palatal to 21. On reappraisal of the origin and pathogenesis of the AOT, it would seem that this tumor or hamartomatous lesion is derived from odontogenic epithelium of the dental lamina complex or its remna

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01363.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

In dyskeratosis congenita, the hyperkeratotic lesions affecting the mucous membranes have a propensity to undergo malignant change. Unfortunately there is presently no reliable method for predicting such an outcome. Oral mucosal biopsies were obtained from a case of dyskeratosis congenial and keratin expression identified using a panel of antikeratin antibodies. Marked changes were found from keratin profiles established for normal oral mucosa. In particular co‐expression of three separate type 1 keratins (K 16, K 10 and K 13) were observed in the ventral tongue lesion. The keratin pattern found in the tissue biopsies examined is suggestive of an unusually immature or disturbed state of tissue differentiation, and as such may be indicative of future malignant chang

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01364.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The diagnosis of some oral mucosal diseases can be facilitated by the use of direct immunofluorescence. Fresh frozen tissue is preferred when using this technique, however frequently the material received by the histopathology laboratory has been fixed in formalin. Enzyme digestion of tissue sections glued to glass slides prior to incubation with antibodies was shown in this study to give comparable results with direct immunofluorescence on fresh frozen tissue and can be used for diagnostic purposes when fresh frozen tissue is unavailable or not representative of the disease process.

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01365.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The occurrence of oral leukoplakia and lichen planus in 1600 patients with diabetes mellitus (815 type 1: insulin‐dependent, 761 type 2: non‐insulin‐dependent) under care at the International Medicine Department ‐ was studied. Prccancerous lesions and conditions were diagnosed and grouped according to internationally accepted criteria. The prevalence of oral leukoplakia in diabetic patients was 6.2%, as compared to 2.2% in the healthy controls, that of oral lichen was 1.0% in the test‐, and 0.0% in the control group. Leukoplakia and lichen both showed the highest occurrence in the second year of established diabetes, and their prevalence was higher among insulin‐treated diabetics. Smokers were more often affected, by both kind of lesions, oral lichen showed a more frequent association with candidiasis. The prevalence of oral leukoplakia and lichen in diabetes mellitus patients was higher, than average ratios in population samples from the s

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01366.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The aim of this investigation was to assess the reproducibility of a study which reported that involucrin could be used as a diagnostic marker in oral lichenoid lesions. Twenty‐eight formalin‐fixed, paraffin‐embedded specimens were examined. They included tissue from 13 patients with lichen planus. 11 with drug‐related lichenoid reactions, one with dysplasia in a lichenoid lesion and three with normal oral mucosa. In each case the biopsy site was the buccal mucosa, PAS stained smears for fungi were negative and immunofluorescence results supported the diagnosis. An immunoperoxidase technique was used to demonstrate involucrin reactivity. In all sections there was consistent positive staining for involucrin in the superficial layers of the epithelium and all the basal layers were negative. In conclusion there were no demonstrable differences in the involucrin reactivity between the different

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01367.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Obstructive sialoadenitis was examined by immunohistochemical techniques for keratin (MoAb K.LI, PKK.I and K.8.12) and actin. Electronmicroscopy (EMS) was used to identify ultrastructural changes in myoepithelial cells and ductal basal cells. With immunohistochemistry, actin staining was used as a marker of myoepithelium. MoAbs KL1 and PKK1 for ductal luminal cells, and MoAb K8.12 for ductal basal cells. Histologic features of the lesion usually showed degenerative changes of acinar and duct cells with cell infiltration and fibrous replacement. Immunohistochemical findings indicated that actin staining in the changed myoepithelial cells was irregularly positive or negative, and also keratin staining in luminal and ductal basal cells was reduced or disappeared. Ultra‐structural features of the changed myoepithelial cells indicated that these cells appeared less altered than adjacent acinar and ductal cells and showed increased amounts of lipid droplets and lipofuscin granules, and also wrinkled processes filled the prominent myofilamenl materia

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01368.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Two new saliva stimulants: V6 and a mucin containing chewing gum were tested in this placebo‐controlled double‐blind crossover study. Forty‐three patients (mean age 63 yr) complaining of dry mouth participated. The products were administered in a randomized order, and used for 2 wk each. The effect was evaluated by interviews and by determining changes in stimulated and unstimulated saliva flow rates. A positive effect was reported by 64%, 44%, and 26% of the patients using the mucin chewing gum, V6, and the placebo, respectively. More than 2/3 of the patients found the mucin chewing gum efficient at various times and situations. Sixty‐one percent of the patients preferred the mucin chewing gum, 21% V6, and 5% the placebo product. Fifty percent of the patients had an increase in unstimulated salivary secretion rate from all products after 14 days regular use indicating a long‐te

ISSN:0904-2512    

DOI:10.1111/j.1600-0714.1992.tb01369.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY